As two-thirds of sensible people will tell you, 75% of statistics are made up on the spot. The more interesting they are, the more likely they are to be nonsense, mathematically speaking. Take this, from last week's news: "10m working days a year are lost because of excessive drinking, at an estimated cost of £960m. Another 72m days are blighted by employees with hangovers. Together they amount to the equivalent of 29m days lost, at a cost to business of £2.8bn."

This demonstrates the power of statistics. On the one hand, it's perfect pub chat fodder: "Do you realise, tomorrow morning I'll have a blighted day, just one of 72m?" But the minute you put these numbers, presented as "facts", under the microscope, strange things start to happen:

1. 10m working days equates to £960m. That means the average British worker's economic value for a full day's work is £96. £96?

2. The hangover statistic of 72m days - where does that number come from? Is there somebody in your organisation responsible for monitoring which employees roll up to work with hangovers? How do they know you've got a hangover? Do they count the number of coffees you drink? And who counts the hangovers when the person counting the hangovers has got a hangover?

3. What constitutes "blighted"? Does the "blighted" employee just need to be a bit quiet in pre-lunch meetings? Or do they have to literally be unconscious by the time the morning tea-trolley comes around?

No industry is more prone to statisticitis than the personal finance industry, and no individual is more worried by stats than the financial hypochondriac. Take property price statistics, which continue to have an at-best elastic relationship with the real world but which also exert a vice-like grip on the anxieties of all hypochondriacs.

On August 19 Guardian Unlimited Money reported figures from the Council of Mortgage Lenders showing that people in the UK took out mortgages worth £29.2 bn in July, up 13% year-on-year. Yet, on August 17, only two days before, the Royal Institution of Chartered Surveyors said that house prices had frozen. And on August 23, Hometrack, a property website, said house prices had actually fallen by 0.1% in July, when all those new mortgages were being taken out.

These statistics are not so much inconsistent as mockingly sadistic. There is so much data flying around the place these days that pretty much anyone can put out a survey saying pretty much anything they want. I'm planning one of my own, saying that 100% of financial hypochondriacs are seriously concerned at the lack of interest shown in personal pensions by spouses. This survey may have had one respondent, but there was a 100% response.

Statisticitis reached new lows (as in, statistics are now 12.3% more worthless than they were a year ago) with the publication of a new survey from esure, the insurance firm that thought putting Michael Winner back on our TV screens was a good idea (and whose commercials have now reached a state of such random incomprehensibility that one must worry about the sanity of their marketing department).

Now, insurance is an industry that relies on statistics more than perhaps any other. Actuaries are paid large amounts of money to detect patterns in events, to work out how much it should cost a chap to insure his Ford Focus in Strathclyde in a world where risk itself is constantly in flux, as is the reliability of the Ford Focus.

What have esure done with this actuarial data goldmine? They've come up with the gem that men called Lloyd are statistically more likely to make a claim on their car insurance than men with any other name. I am thus, statistically, a worse insurance risk than someone called Leon, even though Leon is the worst driver you've ever seen.

Also, statistically speaking, brown cars are more likely to be the subject of claims than any other cars. Now, I don't know anybody else called Lloyd, and I don't know anyone who's got a brown car. So where are all these Lloyds in brown cars? Is there a Welsh close-harmony singing troupe with matching brown Ford Focuses crashing into each other somewhere in the British Isles?

The list of "safe" names in the survey is like a roll-call of characters from Foyle's War: Murray is the safest name in the land, following by Royston, Archie, Terrence and Ernest. Now, if you ask me, men with names like this are far more likely to be driving brown cars than men with excitingly Celtic names like Lloyd. I demand a recount.

On the other hand, statistics can work for you as well as against you, so my next insurance quote could be an interesting affair. Instead of blaming my enormous premiums on the fact that insurance providers seem to think that my neighbourhood is a hotbed of car-crime, I'll be able to play the race card. This high quote - is it because I is Welsh?